Manchester United boss Ole Gunnar Solskjaer admits they were outclassed by Barcelona for their 3-0 Champions League thrashing last night.
United, trailing 1-0 from the first leg, started brightly but were then undone by brilliance from Messi and a glaring mistake from goalkeeper David de Gea.
Messi put the hosts ahead with a fine curling effort from 20 yards in the 16th minute and four minutes later De Gea let a weaker shot from the edge of the area squirm under his body for the Argentine's second.
Philippe Coutinho added a third for Barca in the 61st minute, curling a stunning effort into the top corner from distance.
Solskjaer said on BT Sport: "I have to say Lionel Messi is top quality and he was the difference of course. At 2-0 straight after it was game over.
"He's different class, he and Cristiano Ronaldo are the best players of the last decade, everyone agrees on that one. Messi showed his quality.
"We have to aspire to get to that level of Barcelona, we can get there but we have loads of work to do. If we want to get back to Man Utd's true level, true traditions, we have to challenge Barcelona.
"They were a couple of levels above over the two games. We want to play these games again next year so we have a massive week coming up. There is no point dwelling on what could have been, we have to focus on that week."